Method and system operable to facilitate signal transport over a network

ABSTRACT

A method and system operable to implement a multiple range, and optionally one-dimensional, transport scheduling process suitable to facilitate signal transport over a network for a variety of traffic types with different service requirements where two-dimensional mapping across frequency and/or time is required.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.12/954,079, filed Nov. 24, 2010, now U.S. Pat. No. 8,______, which, inturns, claims the benefit of provisional application 61/266,653, filedDec. 4, 2009, the disclosures of which are hereby incorporated in theirentirety by reference.

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention relates to scheduling transport of data over anetwork, such as but not limited to scheduling transport over a networkhaving network space allocated according to a two-dimensional MAPdefined as a function of frequency and time domains.

2. Background

A network may be configured to transmit data within a range offrequency, which is commonly referred to as the bandwidth of thenetwork. Within that frequency range, minislots, data slots, data unitsor other transmission units may be used to represent portions of thefrequency used at a particular time to support transmission of aparticular piece of data. The size of the minislots may be quantified inbits and/or bytes, e.g., see a minislot defined according to the DataOver Cable Service Interface Specification (DOCSIS). The number ofminislots available at a particular instance in time may be used todefine the network space of the network, i.e., the amount of datatransfer the network can support at any one particular instance in time.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is pointed out with particularity in the appendedclaims. However, other features of the present invention will becomemore apparent and the present invention will be best understood byreferring to the following detailed description in conjunction with theaccompany drawings in which:

FIG. 1 illustrates a scheduling system in accordance with onenon-limiting aspect of the present invention;

FIG. 2 schematically illustrates operation of the scheduling system inaccordance with one non-limiting aspect of the present invention; and

FIG. 3 illustrates a MAP in accordance with one non-limiting aspect ofthe present invention.

DETAILED DESCRIPTION

FIG. 1 illustrates a scheduling system 10 in accordance with onenon-limiting aspect of the present invention. The system 10 may operatein a manner similar to the system described in U.S. patent applicationSer. No. 12/826,889, entitled Multi-Tier Polling, filed Jun. 30, 2010,the disclosure of which is hereby incorporated in its entirety byreference. The system includes an aggregating unit 12 that cooperateswith a plurality of end stations 14 to facilitate any number ofelectronic, communication-based services. The aggregating unit 12 may beoperable to poll each end station 14 individually and adaptively suchthat polling messages or other types of polling related transmissionsmay be individually communicated from the aggregating unit 12 toselective ones of the end stations 14 at selective polling intervals.One non-limiting aspect of the present contemplates relying on thisadaptive polling capability to facilitate management of network space.

The aggregating unit 12 may be any type of device operable to facilitatescheduling transmission between a public network 16 and a privatenetwork 18. The private network 18 may be operable to support privatecommunications between the aggregating unit 12 and the ends stations 14,such as over a closed network or a private virtual network. Thecommunications may be executed through out-of-band (OOB) messaging orother messaging transmission media and/or protocols operable tofacilitate communications between the aggregating unit 12 and the endstations 14. The public network 16 designates the Internet or otherpotentially less secure or non-proprietary networks over which the endstations 14 may transmit signals for receipt by other devices. The endstations 14 may transmit data according to the OOB or a privateprotocol, such as to transmit polling related responses/requests, and/oraccording to protocols used to support IP related communications overthe public network 16.

The aggregating unit 12 is shown as a gateway between the public andprivate networks 16, 18 for exemplary purposes. The aggregating unit 12need not act as a gateway and the present invention is not intended tobe limited to the aggregating unit 12 only supporting communicationsbetween public and private networks 16, 18, as communications may befacilitated over entirely public and/or private networks 16, 18. Thepresent invention contemplates its use in many environments where it maybe desirable to manage network space by facilitating scheduling ofcommunications sourced from one or more of the end stations 14. Theaggregating unit 12 and the end stations 14 may correspond with any typeof electronic device and/or logically executing unit and the networks16, 18 may corresponding with any type or combination of wireline andwireless networks, including but not limited to those associated withcable, satellite, or network television; cellular, wireless, or wirelinephone communications; and wireless or wireline data transmissions.

The present invention is predominately described with respect to a cabletelevision related configuration where the aggregating unit 12 may be acable modem termination system (CMTS) and the private network 18 maycorrespond with a wireline, cable network provided to a subscriber'shome where the end stations 14 may correspond with a cable modem, mediaterminal adaptor (MTA), settop box (STB), television, or other devicedesiring data communications over one or more of the networks to supportcable related services, such as according to communications executedaccording to the Data Over Cable Service Interface Specification(DOCSIS). Of course, the present invention is not limited to cablerelated services or cable dependent communications and fullycontemplates its application within non-cable environments.

One or more of the end stations 14 may be provided in a subscriber'shome, or elsewhere in the event the end station 14 is a mobile device(e.g., PDA, mobile phone, netbook, tablet, etc.), such that it may beoperable to provide or otherwise facilitate access to any number or typeof services, such as but not limited to Voice over Internet Protocol(VoIP), channel surfing (e.g., changing television channels tuned tovideo streams and/or a QAM or IP signaling stream), and fileupload/download through P2P or other operations. One non-limiting aspectof the present invention contemplates managing the processing performedby the end stations 14 and/or aggregating unit 12 to support these andother data transmission dependent services.

Each of the aggregating unit 12 and the end stations 14 may include amemory, processor, I/O and/or other features necessary to implement theoperations contemplated by the present invention. The memory may storecode or other computer readable information to be executed with theprocessor. The stored code may include a layered operating system orarchitecture to support decoupling of the MAC and PHY layers, such as ina manner described in U.S. patent application Ser. No. 12/827,496entitled System and Method of Decoupling Media Access Control (MAC) andPhysical (PHY) Operating Layers, filed Jun. 30, 2010, the disclosure ofwhich is hereby incorporated by reference in its entirety. While notshown, each of the aggregating unit and the end stations may rely in theI/O to support a man-machine interface (MMI), such as to receive aninput from a user or from another device and to facilitate transportingand receiving data over the network.

In accordance with one non-limiting aspect of the present invention theaggregating unit 12 and/or end stations 14 may operate with code havinga convergence layer. The convergence layer may be a logically executinglayer configured to decouple MAC and PHY layers. The convergence layermay be added or otherwise integrated into a layered based architectureused by one or more of the aggregating unit 12 and the end stations 14to facilitate data input and output, such as but not limited to layeredbased architectures organized according Operating System Interconnection(OSI) standard, DOCSIS, IEEE 802.11 standard for wireless local areanetworks (WLAN), IEEE 802.16 for wireless networks (WiMax),code/frequency/time division multiple access code (CDMA/FDMA/TDMA)standards for telephony communications and/or other layered basedarchitectures and standards.

FIG. 2 schematically illustrates operation of the scheduling system 10in accordance with one non-limiting aspect of the present inventionwhere an interaction between one of the end stations 14 and theaggregating unit 12 is described. This illustration is provided forexemplary purposes and to demonstrate a number of possible operationscontemplated by the present invention to facilitate scheduling ofnetwork space and resources. The aggregating unit 12 may be operable torepeat some or all of the described operations with any number of endstations 14, optionally at the same time. The illustrated operationscorrespond with a scenario where the end station 14 receives a transportinput 20 to transmit one or more data packets over the public network 16to which it issues a corresponding transport request 22 to theaggregating unit 12 to schedule the transport thereof.

The transport input 20 is shown to be received from a device (not shown)connected to a home network that is also connected to the end station14. This scenario may arise through user interaction with a computer,STB, MTA, VoIP phone, etc, or other element connected to the homenetwork that results in use of the end station 14 to supportcommunication over the private and/or public networks. Of course, thepresent invention fully contemplates the end station 14 itself having anMMI or other input through which transport inputs 20 may be received.

Prior to actually transporting data packets indicated in the transportinput 20, the end stations 14 may process the input 20 to assess a sizeof the desired transport, e.g., the number of data packets beingtransported, which may be determined from information included withinthe request or dynamically as data is being output after being scheduledfor transport. The number of data packets may be represented accordingto any suitably sized data packet datum and may specify streaming orother continuous transmissions instead of a defined number/size of datapackets. While the number and/or size of the data packets, signals,and/or other information is commonly referred to herein as a datapacket, this nomenclature is not intended to limit the scope andcontemplation of the present invention. This is done to simplify theexplanation as the present invention fully contemplates scheduling anytype of electronic transport over a network where network resources areallocated according to a scheduled-based mechanism.

The end stations 14 may be further operable to assess servicerequirements associated with the transport input 20, e.g., traffic typesor traffic classification criteria. The end station 14 may be operableto support data transport for any number of traffic types andclassifications, such as but not limited to those associated with VoIP,content stream, web/data download, gaming, etc. Some traffic types, suchas web/data download may be tolerant to slower data transmission(greater latency) than other traffic types, such as those associatedwith VoIP and gaming, which may require faster data transmission thanVoIP. Others may require more robustness or efficiency. These latencyand other requirements may be characterized as desired operationalrequirements at least in so far as the services may still be providedeven if the service requirements are not being met, e.g., gaming maystill take place if the desired latency thresholds are exceed at theexpense of user satisfaction, input/output delays, etc. As such, theservice requirements need not necessarily prevent transport duringsituations in which network resources are unable to properly support thelatency requirements.

FIG. 3 illustrates a MAP 30 used to represent network resources of thepublic and/or private networks 16, 18 in accordance with onenon-limiting aspect of the present invention. The MAP 30 may begenerated by the aggregating unit 12 to represent network resources orspace that is available to facilitate network-based data transmission.The MAP 30 two-dimensionally illustrates available network resources asfunction of frequency and time. The frequency and time domains are shownto be further defined as frequency intervals (a-t), referred to assub-channels, and time intervals (A-AB), referred to as sub-frames oflarger frames #1 and #2. (A frame may be considered to be a duration, innumber of sub-frames, over which a set of bandwidth allocation rules aredefined.) The MAP 30 is interchangeable referred to herein as a minislotgrid in that an intersection of each sub-channel and sub-framecorresponds with a minislot (1-530). Each minislot (1-530) may be usedto represent a capacity unit comprised of a number of sub-carriers overtime.

The sub-carriers may be individually defined frequency segmentsmodulated to transfer date within a larger frequency spectrum of thecorresponding sub-channel. The sub-carries may be a more granular orbasic level of communication where the amount of data each sub-carriermay be able to transport can vary according to frequency, networkcharacteristics, etc. The sub-carriers may be grouped and continuouslyre-grouped according to capacity variances to form sub-channels ofconstant capacity. One non-limiting aspect of the present inventioncontemplates collecting or otherwise arranging the sub-carriers suchthat each minislot totals the same capacity, regardless of the actualnumber of sub-carriers being used to form each minislot.

The frequency (sub-channel) and time (sub-frame) coordinates representedalong the vertical axis and the horizontal axis respectively may be usedto identify a starting frequency (start sub-channel) and an encompassedfrequency range (number of sub-channels) as well as a start time (startsub-frame) and a duration (number of sub-frames). These MAP designationsmay be defined according to DOCSIS, and optionally, according to the MACManagement Message that a DOCSIS enabled CMTS would use to allocatetransmission opportunities to a cable modems. The aggregating unit 12 orother device associated with the networks 16, 18 may be responsible forsupporting the MAP 30 and coordinating scheduling and allocation of therelated resources in order to enable the data communications required bythe end stations 14 to support the provided services. In order for thedata packets to be transmitted over the network 16, 18, thecorresponding transport input must be mapped to the two-dimensional MAP30, or a similar two-dimensional MAP, in the event the data is beingtransmitted over the type of network 16, 18 that allocates resources intwo-dimensions as function of frequency and time.

The two-dimensional mapping contemplated by the present invention mayrequire detailed knowledge about available sub-carriers and relatedprocessing in order to properly group the sub-carriers into the samesized (capacity) sub-channels, including capabilities to monitoravailable network resources and continuously changing characteristics ofthe sub-carriers (as one skilled in the art will appreciate, the amountof data each sub-carrier can transport may vary over time according toany number of transient network conditions, such as but not limited tonetwork congestion and utilization levels). The two-dimensional mappingmay also require knowledge of the two-dimensional MAP parameters such asthe MAP duration according to an integer number of frames and/orsub-frames and the number of sub-channels to be used for transmission.These parameters are configurable to achieve the intended performance(i.e. latency, robustness, efficiency etc.).

One non-limiting aspect of the present invention contemplates dividingor segmenting the MAP 30, or more particularly the frames 32, 34comprising the MAP 30, into a plurality of ranges, labeled as first,second, and third ranges 38, 40, 42. The ranges 38, 40, 42 may beportions of the MAP 30 and/or individual frames 32, 34, i.e., networkresources, set aside or otherwise reserved by the aggregating unit 12for certain traffic types or other data transports having particularclassification criteria, e.g., latency, robustness, efficiency, etc. Afirst traffic type, such as gaming or the like, that tolerates a firstamount of latency may be assigned to the first range 38. A secondtraffic type, such as VoIP or the like, that tolerates a second amountof latency may be greater than the first amount may be assigned to thesecond range 40. A third traffic type, such as web/data download or thelike, that tolerates a third amount of latency greater than the secondamount may be assigned to the third range 42. While some ranges arereserved for certain traffic types, other traffic types may be scheduledthereto under some conditions, such as if other ranges are available andthe desired range is full or access to the range is unavailable for anlonger period of time whereby the transport could be completed earlieror more efficiently if scheduled to one of the other ranges.

The aggregating unit 12 may include an algorithm operable to scheduledata packets for transport during one more minislots (1-530) identifiedwithin each of the ranges 38, 40, 42. The aggregating unit 12 mayallocate minislots (1-530) for a particular data packet transportaccording to reference IDs (1-530) assigned to each of the minislots(1-530) within the range dedicated to support transport of thecorresponding traffic type/classification criteria. Optionally, theaggregating unit 12 may be operable to schedule the minislots (1-530)according to a distribution route (shown with arrows in each range 38,40, 42). Different distribution routes may be used for the differentranges depending on whether it is more desirable to favor transportspeed over transport efficiency/robust or transportefficiency/reliability over transport speed. (Transports carried outover less sub-frames tend to complete faster than transports carriedover more sub-frames but with less efficiency/reliability since temporaldisruption are more likely to affect data transported across moresub-channels than sub-frames.)

The minislots found within in the first range are shown to have been setaside to support transport of data packets used to support servicesrequiring low latency or high robustness using short packets. A firstrange distribution route may be used to schedule the minislots withinthe first range 38 in a pattern that generally extends horizontally andthen spirals downwardly. This type of distribution route may becharacterized as having a double-run in that the minislots aresequentially and equally scheduled horizontally across two sub-frames(A, B) within a first sub-channel (a) before being scheduled downwardsone sub-channel (b) to the next two sub-frames (A, B) covering theavailable sub-channels in the sub-channel range (a, b, c, d, e, f)before being scheduled in the same manner in the next sub-frame (C) torepeat the same process. The slope, e.g. rise over run, of the firstrange distribution route is shown to be 0.5 since two minislots arepopulated horizontally before being shifted one minislot vertically.

The minislots found within in the second range 40 are shown to have beenset aside to support transport of data packets used to support servicesrequiring medium latency or medium robustness. A second rangedistribution route may be used to schedule the minislots within thesecond range 40 in a pattern that generally extends horizontally acrossmore than sub-frames than the route of the first range 38 beforeshifting vertically. This type of distribution route may becharacterized as having a greater run than rise in that the minislotsare sequentially scheduled horizontally across the available sub-frames(A, B, C, D, E, F, G) within a selected sub-channel (g) before beingscheduled in the same horizontal manner (A, B, C, D, E, F, G) across thenext available sub-channel (h). Once sub-channel (l) is scheduled in asimilar manner, the second distribution route shifts upwardly back tosub-channel (g) and repeats. This may be done in order to balance thespeed versus latency of services supported with the second range. Theslope, i.e. rise over run, of the second range 40 distribution route isshown to be 0.1429 since seven minislots are populated horizontallybefore being shifted one minislot vertically.

The minislots found within in the third range 42 are shown to have beenset aside to support transport of data packets used to support highlatency and/or high efficiency services. A third range distributionroute may be used to schedule the minislots of the third range 42 in apattern that generally extends horizontally and then downwardly. Thistype of distribution route may be characterized as having a greater runthan rise in that the minislots are sequentially scheduled horizontallyacross all the available sub-frames (A, B, C, D, E, F, G, H, K, I, J, L,M, N) with a selected sub-channel (m) before being scheduled in the samehorizontal manner frames (A, B, C, D, E, F, G, H, K, I, J, L, M, N)across the next available sub-channel (n). This may be done in order tomaximize efficiency/reliability of services supported with the thirdrange. The slope, e.g. rise over run, of the third range distributionroute is shown to be 0.0714 since fourteen minislots are populatedhorizontally before being shifted one minislot vertically.

Frame #2 34 may include the ranges 38, 40, 42 being distributed in thesame manner as Frame #1 31, or as illustrated, in a different manner,such as by increasing the size of the second range 40 when demand forthe first and third ranges 38, 42 decreases or demand for the secondrange increases 40. Frame #2 34 is shown to have the same distributionroutes within each of the corresponding ranges 38, 42, 44 in so far ashaving the same slope but this too may be varied depending on demand orother parameters. Each distribution route is shown to comprising atleast a run of two sub-frames since, at least in many cases, onesub-frame will be needed to support transport of the packet's preamblein order to synchronize transport of the packets payload in at least onesubsequent sub-frame. It may be preferable to include at least a portionof the payload within the same sub-channel before shifting down onesub-channel from the preamble but it is not required, i.e., thedistribution route of the first range 38, for example, may proceed witha greater rise than run by shifting downwardly through two or moresub-channels before shifting rightward one sub-frame, which may bebeneficial if there no preamble is required.

Returning to FIG. 2, the aggregating unit 12 schedules data packettransport upon receipt of the transport request message 22 from the endstation 14. A listing message 48 listing the minislots (1-530) scheduledto support the corresponding transport may then be sent from theaggregating unit 12 to the end station 14. This scheduling is shown tocorrespond with the data packet transport requiring multiple minislots(1-530); however, it may be possible in some cases to transport the datapacket within a single minislot (1-530), depending on the size andcapabilities of each minislot (1-530), which may vary depending on thenetwork configuration and space. The listing message 48 may list anumber of minislots (1-530) scheduled to support the transport accordingto the minislot reference ID assigned thereto. The listing message 48 isconsidered to be a one-dimensional listing/instruction set since theactual sub-channel and sub-frames corresponding with the scheduledminislots (1-530) are not actually identified within the listing message48. The illustrated listing messaging 48 only specifies a referencelocation within the minislot grid (MAP 30), however, the presentinvention fully contemplates include such information with in thelisting message 48 if desired.

A grid message 50 is sent by the aggregating unit 12 with a descriptionof the different ranges of frequency corresponding to a specificminislot routing mechanism i.e. MAP 30. The end station 14 compares thereference IDs included in the listing message 48 to the MAP 30. The gridmessage 50 may be transmitted to the end stations 14 in advance of theminislot listing message 48, at the same time, or thereafter as long asthere is sufficient time to prepare and execute operations required tosupport transport at the appointed time. The minislot grid message 50may include the MAP 30 illustrated in FIG. 3 or another coordinatingsystem that the end station 14 can use to determine the appropriatetwo-dimensional transmission times and frequencies for each of theminislots references included within the listing message 48, therebyallowing the aggregating unit 12 to instruct delivery withoutspecifically identifying sub-channels and sub-frames for each transportrequest.

One non-limiting aspect of the present invention contemplates limitingsome of the processing demands of the aggregating unit 12 by allowingthe aggregating unit 12 to periodically transmit grid messages 50instead of doing so each time a transport request is received.Optionally, the grid message 50 may be used for prolonged periods oftime and/or until sufficient changes occur in network resources thatrequired the adjustment thereof. The separate use of the grid andlisting messages 48, 50 allows the present invention to generateone-dimensional coordinates when scheduling transports that requiretwo-dimensional coordinates due to the ability to the end stations 14 tomap the one-dimensional coordinates to two-dimensional coordinates usingthe layouts provided within the minislot grid messages 50.

Once the end station 14 maps the one-dimensional coordinates to thetwo-dimensional coordinates (sub-channels and sub-frames) required totransport over the network 16, 18, the corresponding data packets aretransported over the private network 18 to the aggregating unit 12 forrelay to the public network 16. The time and frequency of the transport52 may be same over the public and private networks 16, 18, i.e.,according to the mapped to two-dimensional coordinates, such as if thepublic network 16 is under the control of a common entity or isotherwise considered to be part of the private network 18. Optionally,the data packets may be transported to the aggregating unit 12 accordingto some other methodology which embeds the corresponding time andfrequency information mapped to by the end stations 14 within thetransmitted data packets. Each end station 14 and the aggregating unit12 may continue to operate over time in this manner such that each endstation 14, for each desired transport, may request scheduling of thecorresponding data packets from the aggregating unit 12. While theforegoing presumes availability of the sub-frame (A), the scheduling ofany one or more transports may be slotted to any other portion of theMAP 30 and need always begin with the earliest available sub-frame (A),i.e., it can start anywhere within one of the available frames (Frame#1, Frame #2).

The aggregating unit 12 may be operable to dynamically monitor networkcongestion levels, available resources (failure, construction, etc.),and other factors to assess whether the ranges allocated to certaintraffic types or classification criteria are sufficient and whether moreor fewer ranges are required. In the event network congestion levelschange or quality of service requirements are adjusted, the aggregatingunit 12 may adjust the divisions between the ranges 38, 40, 42, eitherby adding or subtracting sub-channels and/or sub-frames. Likewise, inthe event new traffic classification criteria are to be supported or areonly supported during certain periods of time, the ranges 38, 40, 42 maybe altered in a corresponding manner. The ranges 38, 40, 42 areillustrated as being non-overlapping along the horizontal axis in thatone range 38, 40, 42 does not extend into another range 38, 40, 42.However, due to the dynamic capabilities of the present invention, theranges 38, 40, 42 may be adjusted to overlap along the horizontal axis,e.g., in event one range 38, 40, 42 is scheduled for expansion at aperiod to occur after expiration of a yet to be executed minislot(1-530) assigned to another range 38, 40, 42 for the same sub-channel.

As supported above, one non-limiting aspect of the present inventionrelates to segmentation of a two dimensional physical layer environmentinto regions optimized to a specific service requirement. Aone-dimensional scheduling method may be used to allocate data over eachregion in the two dimensional environment. A set of rules of how topopulate data in each region is illustrated. The set of data populationrules enables the translation of data scheduling in a two dimensionalenvironment using a one-dimensional method.

One non-limiting aspect of the present invention relates to a schedulingmechanism operable to allocate data in a two-dimensional environmentthat also allows for decoupling of the MAC and the PHY which reducescomplexity. In addition, the optimizing regions allow transmission ofthe traffic characteristics and service requirements of each traffictypes to be met. The present invention can, in some respects, providesimplifications that can be utilized to reduce the cost and complexityof networking components, including but not limited to headend and CPEequipment in cable, wireless and other industries where two dimensionalmultiple access systems are used.

As required, detailed embodiments of the present invention are disclosedherein; however, it is to be understood that the disclosed embodimentsare merely exemplary of the invention that may be embodied in variousand alternative forms. The figures are not necessarily to scale, somefeatures may be exaggerated or minimized to show details of particularcomponents. Therefore, specific structural and functional detailsdisclosed herein are not to be interpreted as limiting, but merely as arepresentative basis for the claims and/or as a representative basis forteaching one skilled in the art to variously employ the presentinvention. The features of various implementing embodiments may becombined to form further embodiments of the invention.

While embodiments of the invention have been illustrated and described,it is not intended that these embodiments illustrate and describe allpossible forms of the invention. Rather, the words used in thespecification are words of description rather than limitation, and it isunderstood that various changes may be made without departing from thespirit and scope of the invention.

What is claimed is:
 1. A method for scheduling use of network spacecomprising: two-dimensionally defining networks space according to aplurality of sub-channels and sub-frames, each sub-channel intersectingwith one sub-frame to define a minislot; allocating a first portion ofthe sub-channels to support traffic that meets a first classificationcriteria; allocating a second portion of the sub-channels to supporttraffic that meets a second classification criteria; scheduling use ofnetwork space to the allocated one of the first and second portionsdepending on whether a requesting device is requesting to transporttraffic that meets the first or second classification criteria;scheduling transport of traffic within the first portion across a firstpattern of minislots, the first pattern being defined according to a runand a rise, the rise corresponding with a number of sub-channelstraversed and the run corresponding with a number of sub-framestraversed; and scheduling transport of traffic within the second portionacross a second pattern of minislots, the second pattern being definedas having the run greater than the run of the first pattern.
 2. Themethod of claim 1 further comprising dynamically adjusting a size of thefirst and second portions depending on network operating demands.